Table top punch presses are known, and have found wide use in creating perforations in paper materials in preparation for binding. One such punch is the Model 111PM-1 manufactured by the General Binding Corporation.
These punches are typically operable by either a floor-mounted foot switch or a table switch. When the operator wants to use the foot switch, a lockout mechanism is typically provided to prevent actuation of the press by the table switch. The typical lockout mechanism is provided on the paper guide assembly on the press, and includes a locking clamp mounted beneath the paper guide screw assembly. In order to engage the lockout mechanism, the operator must loosen the paper guide screw assembly, then rotate the locking clamp into a position overlying the table switch actuation lever.
Known lockout mechanisms require two-handed operation, one hand to loosen the paper guide screw and another hand to rotate the locking clamp. Furthermore, the locking knobs of known lockout assemblies are susceptible to being inadvertently completely loosened, causing the entire switch and retaining bracket to fall into the machine.